Adhesive composite polyester films

Abstract

Oriented composite polyester films, to which a wide variety of final application topcoatings are improvedly adherent, e.g., matte, photosensitive and magnetic topcoatings, comprise an oriented base film substrate (A) of a crystalline or semicrystalline polyester, the base film substrate (A) bearing an adhesion primer coating (B) on at least one of the face surfaces thereof, and the adhesion primer coating (B) comprising: (a) a crystalline, semicrystalline or crystallizable polyester; (b) a water-sensitive copolyster; and (c) an organic solvent-sensitive polyester or copolyester.

What is claimed is: 
     
       1. An oriented composite polyester film member adapted for adhering an end application topcoating thereon, which comprises an extruded orientated base film substrate (A) comprising a crystalline or semicrystalline polyester, said base film substrate (A) bearing an adhesion primer coating (B) coextruded with the substrate (A) on at least one of the face surfaces thereof, said adhesion primer coating (B) comprising a ternary mixture of: (a) a crystalline, semicrystalline or crystallizable polyester;   (b) a water-sensitive copolyester; and   (c) an organic solvent-sensitive polyester or copolyester.   
     
     
       2. The oriented composite polyester film as defined by claim 1, wherein the polyesters comprising said base film substrate (A) and the component (a) of the ternary mixture are insensitive to ester, ketone and halogenated hydrocarbon organic solvents. 
     
     
       3. The oriented composite polyester film as defined by claim 1, wherein the polyesters comprising said base film substrate (A) and the component (a) of the ternary mixture have a solubility volume below 10 -2  (cal/cm 3 ) 3/2 . 
     
     
       4. The oriented composite polyester film as defined by claim 1, wherein the polyesters comprising said base film substrate (A) and the component (a) of the ternary mixture comprise a homopolyester or a copolyester of terephthalic acid containing at least 80 mole % of terephthalate recurring units. 
     
     
       5. The oriented composite polyester film as defined by claim 4, wherein the polyesters comprising said base film substrate (A) and the component (a) of the ternary mixture comprise polyethylene terephthalate. 
     
     
       6. The oriented composite polyester film as defined by claim 1, wherein the copolyester of component (b) of the ternary mixture comprises a plurality of hydrophilic groups of the general formula:   (-SO.sub.3).sub.n M                                        (I)     in which n is 1 or 2, and M is a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium cation, or a quaternary ammonium cation.   
     
     
       7. The oriented composite polyester film as defined by claim 6, wherein the water-sensitive copolyester of component (b) of the ternary mixture comprises a plurality of recurring units derived from aromatic diacids or derivatives thereof having the formula: ##STR2## in which n is 1 or 2, M is a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium cation, or a quaternary ammonium cation, Z is a polyvalent aromatic radical, X and Y are hydrocarbon radicals, esters of lower aliphatic alcohols, or acid halides, and p is an integer equal to 1 or 2. 
     
     
       8. The oriented composite polyester film as defined by claim 7, wherein the water-sensitive copolyester of component (b) of the ternary mixture comprises a plurality of recurring units of hydroxysulfonylisophthalic acid. 
     
     
       9. The oriented composite polyester film as defined by claim 8, wherein the water-sensitive copolyester of component (b) of the ternary mixture additionally comprises a plurality of recurring units of terephthalic acid. 
     
     
       10. The oriented composite polyester film as defined by claim 9, wherein the water-sensitive copolyester of component (b) of the ternary mixture comprises both a plurality of recurring units of terephthalic acid and a plurality of recurring units of isophthalic acid. 
     
     
       11. The oriented composite polyester film as defined by claim 10, wherein the number of recurring units of isophthalic acid in the water-sensitive copolyester constitutes up to 70% of the total amount of the terephthalate/isophthalate recurring units 
     
     
       12. The oriented composite polyester film as defined by claim 10, wherein the water-sensitive copolyester of component (b) of the ternary mixture comprises a plurality of recurring units of ethylene glycol and/or oligomers thereof having the formula HO--(CH 2  --CH 2  --O) m  --H, in which m is an integer of from 2 to 10. 
     
     
       13. The oriented composite polyester film as defined by claim 12, wherein the amount by weight of recurring units of ethylene glycol oligomers in the water-sensitive copolyester range from 2% to 30%. 
     
     
       14. The oriented composite polyester film as defined by claim 10, wherein the amount of oxysulfonyl group recurring units in the water-sensitive copolyesters, based on the total amount of recurring units of like nature, ranges from 5% to 20%. 
     
     
       15. The oriented composite polyester film as defined by claim 10, wherein the water-sensitive copolyester of component (b) of the ternary mixture comprises from 5 to 20 mole % of recurring units of 5-sulfoisophthalic acid, based on the total amount of recurring units of dicarboxylic acids. 
     
     
       16. The oriented composite polyester film as defined by claim 1, wherein the organic solvent-sensitive polyester of component (c) of the ternary mixture has a solubility volume greater than 10 -2  (cal/cm 3 ) 3/2 . 
     
     
       17. The oriented composite polyester film as defined by claim 16, wherein the organic solvent-sensitive polyester of component (c) of the ternary mixture has a solubility volume greater than 10 -2  (cal/cm 3 ) 3/2  and is not crystallizable. 
     
     
       18. The oriented composite polyester film as defined by claim 17, wherein the organic solvent-sensitive polyester of component (c) of the ternary mixture has a solubility volume greater than 10 -2  (cal/cm 3 ) 3/2  and comprises a copolyester of terephthalic acid, ethylene glycol and oligomers thereof, and further comprises a plurality of recurring units of isophthalic acid and/or aliphatic dicarboxylic acids and/or alkylene diols containing at least 3 carbon atoms. 
     
     
       19. The oriented composite polyester film as defined by claim 18, wherein the organic solvent-sensitive polyester of component (c) of the ternary mixture has a solubility volume greater than 10 -2  (cal/cm 3 ) 3/2  and comprises a noncrystallizable copolyester containing a plurality of recurring units of terephthalic acid, isophthalic acid, ethylene glycol and neopentyl glycol. 
     
     
       20. The oriented composite polyester film as defined by claim 18, wherein the organic solvent-sensitive polyester of component (c) of the ternary mixture has a solubility volume greater than 10 -2  (cal/cm 3 ) 3/2  and comprises a noncrystallizable copolyester containing a plurality of recurring units of terephthalic acid, ethylene glycol and bishydroxymethylcyclohexane. 
     
     
       21. The oriented composite polyester film as defined by claim 1, wherein said ternary mixture comprises: (a) from 30 to 65% by weight of a crystalline, semicrystalline or crystallizable polyester;   (b) from 15 to 60% by weight of a water-sensitive copolyester; and   (c) from 10 to 55% by weight of an organic solvent-sensitive polyester   
     
     
       22. The oriented composite polyester film as defined by claim 1, wherein the thickness of said adhesion primer coating (B) range from 0.3 to 10 micrometers. 
     
     
       23. The oriented composite polyester film as defined by claim 1, wherein at least one adhesion primer coating (B) has an end application topcoating adhered thereto. 
     
     
       24. The oriented composite polyester film as defined by claim 23, said end application topcoating comprising a matte, photosensitive, diazo, magnetic, metallic or print coating.